Oil-fired radiant space heater

ABSTRACT

An oil-fired radiant space heater largely encompassed by heat deflecting louvers comprising an elongated, tub-like bottom part or pan, having a burner at one, the near, end projecting a horizontal flame to the other, the remote, end; the midportion of the pan-bottom comprising a tunnel formed by an inverted channel, the flat top of which comprises a horizontal baffle. the heater also having an upper part overlying said tunnel in open communication therewith at the near and far ends thereof. The upper part of the heater has a closed top which has the flue outlet above the near end of the pan. Said upper part has an open bottom attached and sealed to the upper brim of the pan and has vertical baffles providing a tortuous path for hot gases from the remote end of said bottom part to said flue outlet. One vertical baffle is secured only at its lower end to the said horizontal baffle adjacent the remote end of said tunnel. A second vertical baffle is secured only at its upper end to the top of said upper part near the flue outlet. The upper part of the heater has vertical convoluted side walls to which the vertical baffles are not attached but stand at right angles in a non-confining manner which permits the passage of flue gases around the edges of the baffles and among the convolutions of the side walls; the latter tending to retain the baffles loosely in proper location. The upper part of the heater is made of aluminized steel and the lower part of stainless steel. Both parts are coated externally with black radiant, vitrifying paint.

. Unite States Patrick et a1.

[ Mar. 11, 1975 1 OIL-FIRED RADIANT SPACE HEATER [75] lnventors: Malcolm W. Patrick, Danville;

Joseph W. Adams, Westlake, both of Ohio [73] Assignee: Bettcher Manufacturing Corporation, Cleveland, Ohio [22] Filed: Apr. 5, 1973 [21] Appl. No.: 348,310

[52] US. Cl. 126/91 R, 110/97 D, 237/70 [51] lnt. Cl. F24c 1/10 [58] Field of Search 237/70; 122/155 A, 135 A, 122/135 AE, 44 A, 61, 63, 65, 188, 235 F,

[56] References Cited UNITED STATES PATENTS 366,255 7/1887 Robbins 126/79 767,636 8/1904 Dietz 126/79 2,190,375 2/1940 Curtis 126/91 R 2,733,705 2/1936 Goulding, Sr.... 126/93 3,016,946 l/l962 Ticknor 126/85 R 3,180,322 4/1965 Gibbard 110/97 D FOREIGN PATENTS OR APPLICATIONS 236,196 l/l945 Switzerland 126/85 R [57] ABSTRACT An oi1-fired radiant space heater largely encompassed by heat deflecting louvers comprising an elongated. tub-like bottom part or pan, having a burner at one, the near, end projecting a horizontal flame to the other, the remote, end; the midportion of the panbottom comprising a tunnel formed by an inverted channel, the flat top of which comprises a horizontal baffle. the heater also having an upper part overlying said tunnel in open communication therewith at the near and far ends thereof. The upper part of the heater has a closed top which has the flue outlet above the near end of the pan. Said upper part has an open bottom attached and sealed to the upper brim of the pan and has vertical baffles providing a tortuous path for hot gases from the remote end of said bottom part to said flue outlet. One vertical baffle is secured only at its lower end to the said horizontal baffle adjacent the remote end of said tunnel. A second vertical baffle is secured only at its upper end to the top of said upper part near the flue outlet. The upper part of the heater has vertical convoluted side walls to which the vertical baffles are not attached but stand at right angles in a non-confining manner which permits the passage of flue gases around the edges of the baffles and among the convolutions of the side walls; the latter tending to retain the baffle's loosely in proper location. The upper part of the heater is made of aluminized steel and the lower part of stainless steel. Both parts are coated externally with black radiant, vitrifying paint.

11 Claims, 8 Drawing Figures FATENTED 1 I975 .870.052

SHEU 2 [IF 3 PATENTEU W1 1 I975 sumsurs OIL-FIRED RADIANT SPACE HEATER BACKGROUND OF THE INVENTION Our assignees design U.S. Pat. No. Des. 206,842 illustrates in outward configuration and appearance, our assignees prior and present product, a gas-fired radiant (infra-red) space heater, that preceded our present invention. This gas-fired heater is largely the background against which the instant oil-fired heater has been invented. Gas-fired heaters employ a long, narrow multijet burner in the bottom of a long, narrow and high flame and combustion chamber having closely juxtaposed, convoluted side walls between which the burning gases and hot products of combustion wind tort'u ous, convoluted upward paths, heating and scrubbing heat into the side walls and energizing the side walls to radiant external emission of heat energy. External reflective louvers as shown in the prior patent, and employed herein, divert the radiant heat downwardly. Such heaters are conveniently disposed at a considerable elevation above the floor and working areas to which radiant energy is directed.

The present and impending shortage of fuel gas mothered our present invention of transforming the prior gas-fired heater into an oil-fired one wherein the proven virtues of the former were retained while creating a new and different structure having maximum heat transfer from a minimum number of pounds and square feet of material and accomodating a horizontal oilburner flame with a novel system of baffles in a much wider and shorter flame and combustion chamber, or chambers, than were necessary or advisable in the gasfired heater.

Our oilfired heater was created to employ a conventional oil burner including an air blower to project a large hot flame horizontally in a different way from the prior multi-jet, vertically projected flames of the gas burner. 1

SUMMARY OF THE INVENTION Our invention provides an oil-fired, radiant, space heater and/or heat exchanger that obtains maximum heat transfer with employment of a minimum mass and area of structural material.

Our heater provides a single, large in cross-section, substantial square or rectangular, tortuous main path for flame, hot gases and products of combustion wherein the ratio of radiant surface area to the volume of the heater is apparently worse than in the prior gas-fired practice, due to the overall compactness of our heater. However the thermal, and/or heat exchange, efficiency in our invention has been enhanced by baffling which avoids deleterious flow restriction and promotes high heat exchange and effects wall scrubbing, high velocity paths for hot gases around the detached edges of the baffling. Our heater employs convoluted side walls similar to those in the prior gasfired heater, but provides that they be widely spaced from each other (by the width of the pan, top and end walls) with baffles, normal to the side walls defining said main tortuous path, that are suspended in the space between the side walls in a nonconfining manner which contributes to the passage of flue gases across the edges of the baffles and the adjacent convolutions of the side walls, the latter retaining the baffles loosely in their proper location.

Our invention also provides that the two main upper and bottom parts respectively of the heater be made of different materials for containing flame and hot gases of noticeably different temperatures. The bottom pan part into which the oil-burner and blower project their flame is made of stainless steel externally coated with vitrifying, black, radiant paint and exposes a long, wide bottom surface radiating directly downwardly to the floor or work area where radiation is desired. The upper part stands above the pan and encloses the baffled tortuous path for the hot gases from the remote end of the bottom part to the outlet flue. This part with its convoluted side walls and plain top and end walls is made of aluminized steel and also coated externally with vitrifying paint.

Aluminized steel amalgamates at about I,O00F. at which temperature, and higher, the external paint vitrifles and radiating capacity improves. Gases in the second part of the heater should be kept below about l,l40F. This is about percent of the temperature at which deleterious scaling of the aluminized steel begin to take place. In the stainless steel bottom the same paint will vitrify beneficiently up to l,600-l,800F., and we have found about 1,200F. temperature of flame and burning gases herein satisfactory, providing, inter alia, about 1,000F. on the bottom radiant external painted surface.

Our invention also provides the aforesaid horizontal baffle above and enclosing the mid-portion of the said bottom providing a tunnel part having vertical openings partly exposed in said upper part which minimize initial ignition concussion and permit some hot gases to recirculate and improve combustion, and, indirectly, improve heat transfer.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation ofthe heater embodying our invention with heat deflecting louvers attached; the known and prior burner and blower being shown in dot and dash lines.

FIG. 2 is an end elevation of our heater taken on the broken line 2-2 of FIG. 1.

FIG. 3 is a top plan view of our heater.

FIG. 4 is a side elevation of our heater with the burner and blower inlet and the flue outlet on the left as viewed; the near side-wall being largely cut away to show the vertical and horizontal baffles in full lines.

FIG. 5 is a fragmentary side elevation of one of the like pair of the convoluted side walls of our heater.

FIG. 6 is a vertical section taken on the line 6-6 of FIG. 5 with a fragment of one of the vertical bafflesjuxtasposed in operative relation to the side wall.

FIG. 7 is a horizontal section of part of the side wall taken along the line 7-7 of FIG. 5 including the fragment of said baffle.

FIG. 8 is an end elevation of the tunnel under the horizontal baffle with the channel only mounted on the bottom pan.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Our heater H, FIGS; 1-4 inclusive, except for part of the pan P and top panel 10, is covered externally with heat reflecting louvers L, has a conventional oil burnerblower unit B mounted at and adjacent to the near, right end as viewed, of the pan P whence it projects its flame horizontally to and toward the far end of the pan and heater. A radiant heat shield S is interposed between the heater H and blower-burner B. Flame, incadescent gases, products of combustion and flue gases at sequentially lower temperatures follow a main, generally tortuous, path in the upper, heat-transfer part T of the heater H, as suggested by the arrows a, from burner B and pan P to the flue outlet F in the top panel 10.

As suggested in FIGS. 2 and 4 the burner-blower assembly includes an appropriate mounting structure 12 having a horizontal cylindrical discharge passage 13 from which the burner flame is projected longitudinally of the pan. The structure 12 is partially duplicated at 14 at the far end of the heater; both structures serving to join the pan P and the upper part T together and reinforce the whole assembly of the component parts of the heater.

Mounted above the mid-portion of the pan within the upper portion of the heater is a baffle 15, FIGS. 2, 4 and 8, comprising the stiffened and embossed top of the inverted channel member 16. The channel member 16 with the mid-portion of the pan comprises the tunnel N which is open at both ends at 17 and 18, FIG. 4, so that some of the gases projected from the burner B may take a vertically curved short cut through the far opening 18, arrow al, from the pan to the far end of the upper part T of-the heater. The opposite, near, opening 17 overlies the outrushing flame and air blast from the blower-burner and permits flue gases to be sucked down into the pan and/or under baffle 15 and recirculated with the flame and incadescent gases in the tunnel N as suggested by the arrow a2 FIG. 4. Such recirculation improves combustion and, indirectly, improves heat transfer from burning fuel to external radiant heat. Channel 16 with its open ends also tends to minimize initial ignition concussion by virtue of providing free plural paths from the burner to the flue outlet.

As shown in FIGS. 2-7 inclusive, the upper, heattransfer part T comprises convoluted side walls 20, the bottom ends of which bear upon and overlap the top flanged sides of the brim of the pan P, as at 21, FIGS. 2 and 4. The flanged edges 22 of the side walls 20 have air-tight engagement with the complimentary side flanges 23 of the top panel and the flanged edges of the end walls. A removable inspection plate 26 has airtight engagement with the top panel 10. All the constituents of the heater H that are exposed to atmosphere are bolted, bonded and/or welded at their exposed joints and connections, to admit no communication with atmosphere except only via the burner-blower B and flue F.

Referring to FIGS. 4-7 inclusive, like vertical baffles 28 and 29 guide the hot products of combustion in a main tortuous path suggested by the arrows a. The baffle 29 is secured only at its bottom flanged end to the horizontal baffle with its top end spaced below the top 10 of the heater. Baffle 29 guides flame and hot gases upwardly at the far end of the heater where they are then turned downwardly toward baffle 15. The interior of the highest part of the top panel 10 is freely and vigorously swept by the main stream of hot gases and admits no pocketing of unburned gas in this area The baffle 28 is secured only at its flanged top end near the flue outlet F, not necessarily quite as remotely from the near, leftward as viewed, end wall as shown. The lower end of baffle 28 is spaced above the horizontal baffle 15 to accomodate the 180 turn of the path of flow of and the convolutions 30 thereof, FIGS. 6 and 7. Part of the main body of the gases are encouraged to flow between the side edges of the baffles 28 and 29, and the convolutions 30 as suggested by the arrow b curving around the edge 28a of baffle 28 in FIG. 7. We prefer that the baffles be straight edged and have flat pyramidal form for stiffness as shown in FIGS. 4 and 7 and as suggested by the dot-dash diagonal lines in FIG. 6. End panels 25 are similarly stiffened, FIG. 2. In all events hot gases will be scrubbed through various of the convolutions 30 in the side walls 20 with enhanced heat transfer thereto. It follows that the whole main tortuous stream of flame flue gas etc. will have a continuous churning, eddying, short-cutting turbulence between the sides and middle of the stream tending mightily to transfer the heat from the middle of the stream to the radiating side walls of the heater.

The numerous and various clearances between the edges of the baffles and the side walls taken with the absence of any harmful pocket under the top 10 also avoids a sealed diving flue design which permits our oilfired heater to be converted to gas.

While we have illustrated and described a preferred form of our invention changes and improvements will occur to those skilled in the art without departing from the principles and precepts thereof that are taught and disclosed herein. We, therefore, do not want our patent to be restricted to the particular forms and manifestations herein disclosed, nor limited in any way inconsistent with the progress in the art that-has been promoted by our invention.

We claim:

1. In a radiant space heater having a part through which hot gases are moved in a tortuous path defined by relatively staggered baffles and confined by side walls adjacent the edges of said baffles and adapted to receive heat from said moving gases internally and radiate heat externally, the improvement comprising that the edges of said baffles are disposed within said part in a non-confining manner which permits the passage of flue gases across the edges of the baffles adjacent said side walls and does not rerestrict all the movement of all said gases to said path and does supplement the flow of gases in said path and does induce scrubbing movement of part of said gases on said walls in thin, shortcut streams adjacent to the edges of said baffles.

2. The improvement of claim 1 wherein said side walls are convoluted and provide said short-cut streams in different sizes, and tend to retain said baffles loosely in relation to said convolutions.

3. A radiant space heater comprising a lower, elongated upwardly open pan part made of material resistant to high flame temperature and having a radiant external horizontal bottom, and vertical end and side surfaces, an upper, elongated upwardly-closed, heat transfer part with its bottom tightly fitted to the open top of said lower part and made of material greatly receptive of heat absorption on its inwardly facing surfaces and having its external surfaces prepared to emit the maximum radiant heat, said upper part having a top portion with a flue opening and convoluted vertical walls in contact with which hot gases are conducted, said lower part being adapted to convey flame horizontally from one end to the other, means inducing movement of hot gases from said other end of said lower part into said upper part, staggered baffles in said upper part tending to direct movement of said gases in a tortuous path bounded on its sides by said convoluted walls, said baffles standing normal to said walls with their edges detached therefrom to permit part of said gases to depart variously from said path and scrub said walls around the edges of said baffles.

4. The heater of claim 3 wherein said means includes a cover for the mid-portion of said lower part having its ends exposed in said upper part and providing a vertical opening near said one end of said lower part through which relatively cool gases from said upper part may be drawn by said flame into said lower part and recirculated through the heater.

5. The heater of claim 4 with one of said baffles secured only to said cover adjacent said vertical opening, and another baffle secured only to said top portion adjacent said flue opening.

6. An oil-fired radiant space heater comprising a lower pan part which is wide and deep relative to its length and is adapted to convey flame from its near end to its far end, a tunnel in the middle of said pan open at both its near and far ends, an upper heat transfer part having a top wall with a flue outlet, baffles in said heat transfer part guiding gases from the far end of said pan part to said flue outlet, said parts having about the same length and width, and their combined height being about the same as their length, said, tunnel at its near end admitting part of said gases from said heat transfer part for recirculation through the pan part, one of said baffles being attached to and rising from the far end of said tunnel toward said top wall, another of said baffles depending from said top wall and guiding gases onto said tunnel.

7. A radiant space heater having radiant convoluted widely-spaced side walls, relatively staggered baffle means for guiding a main tortuous stream of hot gases between said side walls, said baffle means standing normal to said side walls with edges adjacent but detached therefrom and permitting hot gases to flow in thin short-cut streams around said edges and into heatscrubbing contact with the convolutions of the side walls, said short-cut stream augmenting the flow of gases in said main stream.

8. The heater of claim 7 wherein said baffle means comprises a baffle around one end of which said main stream makes a reentrant turn and flows in opposite directions on opposite sides of said baffle, said short-cut streams flowing from upstream to downstream of said main stream around the said edges.

9. A radiant space heater having radiant convoluted side walls, baffle means for guiding a main stream of hot gases between said side walls, said baffle means standing normal to said side walls with edges adjacent but detached therefrom and diverting hot gases around said edges and into heat-scrubbing contact with the convolutions of the side walls, said heater having near and far end walls, a top wall and a bottom pan with an upper peripheral brim connected to the bottoms of said side walls and end walls, said top wall having only a flue opening at its near end and said pan having only a flame inlet opening and passage at its near end. said pan also having a tunnel in its midportion with near and far end openings facing and spaced from said near and far end walls respectively, said baffle means including one baffle standing on the top of said tunnel above said far opening and juxtaposed to said far end wall and confining the said main stream of hot gases to move upwardly from said pan between said baffle and said far end wall.

10. The heater of claim 9 wherein said baffle means also includes another baffle depending from said top wall near said flue opening and spaced at its lower end from said tunnel and juxtaposed to said near end wall, said another baffle turning said main stream to flow toward said near end wall and move upwardly to said flue opening and downwardly to the near opening of said tunnel.

11. In a radiant space heater having a part through which hot gases are moved in a tortuous path defined by relatively staggered baffles and confined by side walls adjacent the edges of said baffles and adapted to receive heat from said moving gases internally and radi' ate heat externally, the improvement comprising that the edges of said baffles are suspended within said part in a non-confining manner which contributes to the passageof flue gases across the edges of the baffles and does not restrict all the movement of all said gases to said path and does induce scrubbing movement of part of said gases on said walls in short-cut streams adjacent to the edges of said baffles, said heater also comprising another lower pan-shaped part attached to the lower ends of said side walls and having a central tunnel adapted to direct flame and hot gases lengthwise of said lower part of said tortuous path, one of said baffles being attached to one end of said tunnel and another baffle directing said tortuous path toward the other end of said tunnel. 

1. In a radiant space heater having a part through which hot gases are moved in a tortuous path defined by relatively staggered baffles and confined by side walls adjacent the edges of said baffles and adapted to receive heat from said moving gases internally and radiate heat externally, the improvement comprising that the edges of said baffles are disposed within said part in a non-confining manner which permits the passage of flue gases across the edges of the baffles adjacent said side walls and does not rerestrict all the movement of all said gases to said path and does supplement the flow of gases in said path and does induce scrubbing movement of part of said gases on said walls in thin, shortcut streams adjacent to the edges of said baffles.
 2. The improvement of claim 1 wherein said side walls are convoluted and provide said short-cut streams in different sizes, and tend to retain said baffles loosely in relation to said convolutions.
 3. A radiant space heater comprising a lower, elongated upwardly open pan part made of material resistant to high flame temperature and having a radiant external horizontal bottom, and vertical end and side surfaces, an upper, elongated upwardly-closed, heat transfer part with its bottom tightly fitted to the open top of said lower part and made of material greatly receptive of heat absorption on its inwardly facing surfaces and having its external surfaces prepared to emit the maximum radiant heat, said upper part having a top portion with a flue opening and convoluted vertical walls in contact with which hot gases are conducted, said lower part being adapted to convey flame horizontally from one end to the other, means inducing movement of hot gases from said other end of said lower part into said upper part, staggered baffles in said upper part tending to direct movement of said gases in a tortuous path bounded on its sides by said convoluted walls, said baffles standing normal to said walls with their edges detached therefrom to permit part of said gases to depart variously from said path and scrub said walls around the edges of said baffles.
 4. The heater of claim 3 wherein said means includes a cover for the mid-portion of said lower part having its ends exposed in said upper part and providing a vertical opening near said one end of said lower part through which relatively cool gases from said upper part may be drawn by said flame into said lower part and recirculated through the heater.
 5. The heater of claim 4 with one of said baffles secured only to said cover adjacent said vertical opening, and another baffle secured only to said top portion adjacent said flue opening.
 6. An oil-fired radiant space heater comprising a lower pan part which is wide and deep relative to its length and is adapted to convey flame from its near end to its far end, a tunnel in the middle of said pan open at both its near and far ends, an upper heat transfer part having a top wall with a flue outlet, baffles in said heat transfer part guiding gases from the far end of said pan part to said flue outlet, said parts having about the same length and width, and their combined height being about the same as their length, said tunnel at its near end admitting part of said gases from said heat transfer part for recirculation through the pan part, one of said baffles being attached to and rising from the far end of said tunnel toward said top wall, another of said baffles depending from said top wall and guiding gases onto said tunnel.
 7. A radiant space heater having radiant convoluted widelyspaced side walls, relatively staggered baffle means for guiding a main tortuous stream of hot gases between said side walls, said baffle means standing normal to said side walls with edges adjacent but detached therefrom and permitting hot gases to flow in thin short-cut streams around said edges and into heatscrubbing contact with the convolutions of the side walls, said short-cut stream augmenting the flow of gases in said main stream.
 7. A radiant space heater having radiant convoluted widely-spaced side walls, relatively staggered baffle means for guiding a main tortuous stream of hot gases between said side walls, said baffle means standing normal to said side walls with edges adjacent but detached therefrom and permitting hot gases to flow in thin short-cut streams around said edges and into heat-scrubbing contact with the convolutions of the side walls, said short-cut stream augmenting the flow of gases in said main stream.
 8. The heater of claim 7 wherein said baffle means comprises a baffle around one end of which said main stream makes a reentrant turn and flows in opposite directions on opposite sides of said baffle, said short-cut streams flowing from upstream to downstream of said main stream around the said edges.
 9. A radiant space heater having radiant convoluted side walls, baffle means for guiding a main stream of hot gases between said side walls, said baffle means standing normal to said side walls with edges adjacent but detached therefrom and diverting hot gases around said edges and into heat-scrubbing contact with the convolutions of the side walls, said heater having near and far end walls, a top wall and a bottom pan with an upper peripheral brim connected to the bottoms of said side walls and end walls, said top wall having only a flue opening at its near end and said pan having only a flame inlet opening and passage at its near end, said pan also having a tunnel in its midportion with near and far end openings facing and spaced from said near and far end walls respectively, said baffle means including one baffle standing on the top of said tunnel above said far opening and juxtaposed to said far end wall and confining the said main stream of hot gases to move upwardly from said pan between said baffle and said far end wall.
 10. The heater of claim 9 wherein said baffle means also includes another baffle depending from said top wall near said flue opening and spaced at its lower end from said tunnel and juxtaposed to said near end wall, said another baffle turning said main stream to flow toward said near end wall and move upwardly to said flue opening and downwardly to the near opening of said tunnel. 